The invention relates to a device for the dewatering of naturally moist lump peat in its natural obtained state and without flocculation agent through pressing, which device has an inlet part for the material which is to be treated, means following on from this for the extrusion of a filtrate via screens and for the collection of the filtrate, and also washing devices for the repeated cleaning of the screens and for the collection of the used cleaning water, in particular a continuously operating machine wire press.
Such a machine wire press for the dewatering of lump peat is shown for example in the U.S. Pat. application Ser. No. 359,584, filed Mar. 18, 1982, now pending. The gathered lump peat, is very heterogeneous in terms of particles, ie. it has a very broad particle size spectrum, from fine fibres to coarse pieces. Before the dewatering, the natural peat is crushed, which additionally exposes the fine fractions. For reasons of economy it is necessary to use coarser meshed screens in the press in order to carry off considerable quantities of filtrate which are to be removed. This leads to considerable quantities of the finer fractions of the treated material being rinsed away. This means not only a loss of the matter, but also losses to quality, since the fine and finest fractions would be very desirable in the final product.
It is usual, today, to collect and eliminate the filtrate at the points it accumulates, just as the fluid used for the washing, rinsing of the filters, which also has a considerable proportion of fine fractions.
It had already been considered, to separate these suspensions and to add the particle slurry, gained principally through sedimentation, into the material which is to be processed. This present method leads, however, to the final product firstly having a variable proportion of the fine fractions through an intermittent input, and through a temporary delay components which are alien to each other come together. Particles are added to a peat harvested later, which originate from an earlier harvest or from another locality.
However, it is required of the final product that it has a quality totally corresponding to or the same as that harvested, as regards the composition both in terms of particle spectrum and also in terms of substance.